Shock Absorber Tunnel Assembly for Frontal Impact Energy Management
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Solution Overview
Problem
Current motor vehicle body structures fail to adequately reduce occupant deceleration during frontal impacts, as energy absorption solutions do not effectively limit the transmission of shock forces to the passenger compartment, leading to sudden and dangerous deceleration and potential intrusion of the powertrain.
Innovation Solution
An assembly comprising a transverse apron and a longitudinally extending tunnel with a shock absorber positioned beyond the apron in the engine compartment, designed to deform and absorb energy, thereby reducing the transmission of shock forces to the passenger compartment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the powertrain is allowed to come to rest against the bulkhead to absorb impact energy, then the energy absorption function is improved, but the deceleration felt by occupants becomes abrupt and dangerous
Solution Approach 1:
A shock absorber is introduced as an intermediary element between the powertrain and the bulkhead. This shock absorber progressively absorbs impact energy through controlled deformation, preventing direct contact between the powertrain and bulkhead. The shock absorber acts as a mediator that transforms the abrupt energy transfer into a controlled, progressive deformation process, thereby reducing harmful deceleration forces transmitted to the passenger compartment while maintaining effective energy absorption.
Solution Approach 2:
The shock absorber is pre-installed in the tunnel between the powertrain and bulkhead to provide beforehand cushioning. This pre-positioned energy absorption mechanism ensures that when impact occurs, the shock absorber is already in place to progressively absorb energy through controlled deformation, preventing the powertrain from directly impacting the bulkhead and causing abrupt deceleration to occupants.
2Loss of energy
If the front part of longitudinal members deforms to absorb energy, then energy absorption is improved, but the powertrain may still penetrate the firewall and enter the passenger compartment
Solution Approach 1:
The shock absorber serves as a mediator that provides progressive resistance to powertrain movement during impact. Unlike the longitudinal members that deform to absorb energy, the shock absorber maintains structural integrity while controlling powertrain displacement, ensuring the powertrain remains contained within the engine compartment and cannot penetrate the firewall into the passenger compartment.
Solution Approach 2:
The impact energy absorption function is segmented between two independent systems: the longitudinal members that deform to absorb initial impact energy, and the shock absorber that provides progressive resistance to contain the powertrain. This segmentation allows each component to specialize in its specific function, ensuring both energy absorption and reliable powertrain containment without compromising either function.
3Strength
If existing force transmission elements are installed to divert impact force from the bulkhead, then bulkhead protection is improved, but deceleration reduction for occupants is not achieved
Solution Approach 1:
The shock absorber is positioned as an intermediary element between the powertrain and bulkhead, fundamentally different from existing force transmission elements that connect the bulkhead to the floor or deck. This intermediate positioning allows the shock absorber to progressively absorb impact energy through controlled deformation, thereby reducing the deceleration forces transmitted to the passenger compartment while still protecting the bulkhead from direct impact.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The shock absorber effectively absorbs energy from frontal impacts, reducing occupant deceleration and preventing powertrain intrusion into the passenger compartment, enhancing safety by dissipating impact forces before they reach the passenger compartment.
Implementation Method 1
a shock absorber (17) installed on a second section (16) of the tunnel extending beyond the apron (11), into the engine compartment (102), by a second section (16) on which is installed a shock absorber (17) designed to deform by absorbing energy
Data Source
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AI summary
The invention relates to an assembly (10) for a motor vehicle body structure extending from rear to front along a longitudinal direction (X), the assembly (10) comprising: - a transverse apron (11) extending between a lower transverse edge (12) and an upper transverse edge (13) to separate an engine compartment (102) intended to house a powertrain from a passenger compartment (101) located at the rear relative to the engine compartment (102), - a tunnel (14) extending along the longitudinal direction (X) and comprising a first section (15) located in the passenger compartment (101), the first section (15) of the tunnel (14) extending beyond the apron (11), into the engine compartment (102), by a second section (16) on which is installed a shock absorber (17) designed to deform by energy absorption.